<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            padding: 0;
            margin: 0;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
    <h1>hello world</h1>
    <input id="root"/>
    <script>
        var input=document.getElementById('root')
    </script>
</body>
</html>